Please note this is just an Archive Site of old British Amateur Electronics Club Material. The Club consisted of over 140 Quarterly Printed Newsletters in total. I will be adding some interesting articles from old Newsletters, and other sources plus links etc... So keep an eye on the site. I will flag it clearly with a NEW gif at the top of the page if there is any new material. The Club also traded electronic components among Members, and gave Technical Advice. I for example sent an Infra-Red Remote Control I had made away to another member for Calibration. I have also contributed some articles to the Newsletter myself.

Post a request to
EPE Magazine Chatzone for electronics technical questions. Run by the 'Everyday Practical Electronics' Hobbyist Magazine. A merger of two once very popular magazines (pre the advanced computers age).

Engineering Measurements
from yocto, to zepto, atto, to femto, to pico, to angtrom, to nano, to micro, to milli, to centi, to deci, to deca, hecto, to kilo, to mega, to giga, to tera, to peta, to exa, to zetta, to yotta............ to tebi...................................... to google......................................................................... to googleplex.

Transformer which steps a Voltage down, at a ratio of 40:1 in this case, depending on how many wire turns each side has, from 'primary' side to 'secondary' side. Current goes down from 1A -> 1/40A or 25mA in an 'ideal' 100% efficient circuit. In actual fact 20% of current is wasted as heat in the conversion process.

Bridge Rectifier Circuit which converts A.C. -> D.C. using a network of 4 diodes giving a 'ripple current'. Obiwan posts to EPE ChatZone on Thursday, 15 June:
"Diodes have ratings, I select a diode for it's application if it isn't already in my box of 'goodies'. A 1N4001 that I might use in a simple power supply, say 100 mA, I will not use in one that delivers 10 Amps."

This has to be 'smoothed' using a Electrolytic Smoothing Capacitor which is connected from Vcc output to Gnd. Obiwan continues: "The value will depend on the current rating you are dealing with. A 5V power supply that supplies 10 mA will have a MUCH smaller capacitor than a supply that supplies 5V @100A."

Doorbell for the Deaf by S. R. Wooding. Built using x4 2-input NOR Gates, a 10-line decade counter, and an opto-Triac which isolates the low voltage logic from the mains, while allowing it to trigger a 25W mains driven lamp. Plus some discrete components. With circuit diagram.

About the PIC 16F84. First details a digital circuit to count in binary on LEDs using a 555 Timer and
CMOS 4024 7-bit (÷128) Ripple Counter Chip plus 2 resistors, 3 capacitors and 7 LEDs. Constructed on plugboard, no soldering. Then shows how a PIC can do the exact same thing using only one IC (Integrated Circuit) with only 2 resistors, a capacitor and again off course 7 LEDs. The PIC is programmed using a PIC BASIC compiler (PBC) to produce HEX (Hexadecimal, base 16: 0-9 + A-F) code. So no need to know about op-codes, assembler, the accumulator, status register (flags: zero, carry, division-by-zero error...), stack, ALU (Arithmetic and Logic Unit, does logic and addition) fetch-execute cycle... Then goes on to show how the PIC can be re-programmed to do a different task. Impossible for the digital circuit! Less components and more functions.

Membership is FREE. Members E-mail Addresses, Experience, Interests, Qualificatons... are listed. Feel free to send in you details, particularly projects of interest, and links to any electronics related sites you have. The Club no longer publishes and posts a Newsletter! Although sent in articles etc... will still be published on the 'net.

[Michael] Faraday Museum: at the Royal Institution, 20 Albermarle Street, Near Piccadilly Circus and Green Park Underground Stations, London.Admission Charge. Open 10 a.m. to 6 p.m. Mon. to Fri.
Pioneer in the field of Electricity and Electronics. Inventor of: the Capacitor (the unit of Capacitance the Farad in named for him: F, more commonly µF), the motor (using a mercury 'well' as conductor), the dynamo...

The Science Museum, Exhibition Road, South Kennsington Underground Station (with tunnel walkway that leads directly to the Museum), London.No Admission Charge. Open 10 a.m. to 6 p.m. Open every day except 25th, 26th, and 27th December.
New Exhibits. Exhibits include the Computing Section and Charles Babbages Mechanical Difference Engine ; and Electronic Tele-Communications. Plus much, much more. 6 floors!

Webmaster pictured with Babbage's Difference Engine No. 2. A primitive Victorian Mechanical Computer made to calculate logarithms for navigation. It never worked as Victorian Engineering wasn't precise and cheap enough, and Babbage's temperament wasn't good either, but the design was sound and has been proved to be correct.
Pictures and Description of Babbages Difference Engine.

Programmes to Download FREE

Colour code convertor -
The colour code convertor is a special purpose computer program which will help you identify the value of a resistor from its colour code. Alternatively, the program lets you find out what colours to look for by typing in or selecting the resistor value.
The programme works with Windows 95 and is FREE to download.